The present invention relates to a modular control assembly, especially for electronic control and automation systems with housing blocks that can be lined up next to each other. Bus conductor segments of an internal bus conductor are arranged with movable contact members for the electrical connection of the bus conductor segments of neighboring housing blocks and with electronics modules that can be mechanically connected with the housing blocks via a plug connection and that can also be connected to the bus conductor segments via a plug connection in an electrically conducting fashion.